Display Device

ABSTRACT

A display device capable of reducing a non-display area includes a substrate hole surrounded by light emitting elements, and a moisture penetration preventing layer disposed between an inner dam surrounded by the light emitting elements and the substrate hole. Accordingly, it is possible to prevent damage to light emitting stacks caused by external moisture or oxygen. Since the substrate hole is disposed within an active area, a reduction in non-display area is achieved.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application claims the benefit of Republic of Korea PatentApplication No. 10-2018-0161834 filed on Dec. 14, 2018, which is herebyincorporated by reference as if fully set forth herein.

BACKGROUND Field

The present disclosure relates to a display device, and moreparticularly to a display device capable of reducing a non-display area.

Discussion of the Related Art

An image display device, which renders a variety of information on ascreen, is a core technology of the information age. Such an imagedisplay device is developing towards enhanced thinness, enhancedlightness, and enhanced portability as well as enhanced performance. Inconnection with this, a flat display device capable of eliminatingdisadvantages of heavy and bulky structures of cathode ray tubes (CRTs)is highlighted.

Representative examples of such a flat display device may include aliquid crystal display (LCD) device, a plasma display panel (PDP), anorganic light emitting display (OLED) device, an electrophoretic display(ED) device, and the like.

Such a flat display device is employed in various types of appliancessuch as a television (TV), a monitor and a portable phone, and is beingfurther advanced through addition of a camera, a speaker and a sensorthereto. However, the camera, the speaker, the sensor and the like aredisposed in a non-display area of the display device and, as such, abezel area, which is a non-display area, increases. For this reason,there may be a limitation in maximizing a display area in the displaydevice.

SUMMARY

Accordingly, the present disclosure is directed to a display device thatsubstantially obviates one or more problems due to limitations anddisadvantages of the related art.

An object of the present invention is to provide a display devicecapable of reducing a non-display area.

Additional advantages, objects, and features of the invention will beset forth in part in the description which follows and in part willbecome apparent to those having ordinary skill in the art uponexamination of the following or may be learned from practice of thedisclosure. The objectives and other advantages of the disclosure may berealized and attained by the structure particularly pointed out in thewritten description and claims hereof as well as the appended drawings.

To achieve these objects and other advantages and in accordance with thepurpose of the disclosure, as embodied and broadly described herein, adisplay device includes a substrate hole surrounded by light emittingelements, and a moisture penetration preventing layer disposed betweenan inner dam surrounded by the light emitting elements and the substratehole. Accordingly, it may be possible to prevent damage to lightemitting stacks caused by external moisture or oxygen. Since thesubstrate hole is disposed within an active area, a reduction innon-display area may be achieved.

It is to be understood that both the foregoing general description andthe following detailed description of the present invention areexemplary and explanatory and are intended to provide furtherexplanation of the invention as claimed.

BRIEF DESCRIPTION OF THE DRAWINGS

The accompanying drawings, which are included to provide a furtherunderstanding of the invention and are incorporated in and constitute apart of this application, illustrate embodiment(s) of the invention andalong with the description serve to explain the principle of thedisclosure.

FIG. 1 is a view illustrating an organic light emitting display devicehaving a substrate hole according to an embodiment of the presentdisclosure.

FIG. 2 is a cross-sectional view taken along line I-I of FIG. 1,illustrating the organic light emitting display device in which thesubstrate hole has a structure according to a first embodiment of thepresent disclosure.

FIG. 3 is a plan view concretely illustrating a substrate hole areashown in FIG. 1 according to an embodiment of the present disclosure.

FIG. 4 is a cross-sectional view illustrating a camera module fitted ina substrate hole illustrated in FIG. 2 according to an embodiment of thepresent disclosure.

FIG. 5 is a cross-sectional view illustrating an organic light emittingdisplay device having a substrate hole according to a second embodimentof the present disclosure.

FIGS. 6A to 6C are cross-sectional views illustrating differentembodiments of a light emitting stack and a moisture penetrationpreventing layer illustrated in FIG. 5, respectively, according toembodiments of the present disclosure.

FIG. 7 is a cross-sectional view illustrating an organic light emittingdisplay device having a substrate hole according to a third embodimentof the present disclosure.

FIGS. 8A to 8H are cross-sectional views explaining a method formanufacturing the organic light emitting display device having thesubstrate hole illustrated in FIG. 7 according to an embodiment of thepresent disclosure.

FIG. 9 is a cross-sectional view illustrating an organic light emittingdisplay device having a substrate hole according to a fourth embodimentof the present disclosure.

FIGS. 10A to 10D are cross-sectional views explaining a method formanufacturing the organic light emitting display device having thesubstrate hole illustrated in FIG. 9 according to an embodiment of thepresent disclosure.

FIG. 11 is a cross-sectional view illustrating an organic light emittingdisplay device having a substrate hole according to a fifth embodimentof the present disclosure.

FIGS. 12A to 12C are cross-sectional views explaining a method formanufacturing the organic light emitting display device having thesubstrate hole illustrated in FIG. 11 according to an embodiment of thepresent disclosure.

DETAILED DESCRIPTION

Hereinafter, preferred embodiments of the present disclosure will bedescribed in detail with reference to the accompanying drawings.

Referring to FIGS. 1 and 2, a display device is illustrated. The displaydevice includes an active area AA and a non-active area NA.

The non-active area NA is an area except for the active area AA. Aplurality of pads 180 is disposed in the non-active area NA. Theplurality of pads 180 supply drive signals to a plurality of signallines 106 disposed in the active area AA, respectively. Here, eachsignal line 106 includes at least one of a scan line SL, a data line DL,a high-voltage (VDD) supply line or a low-voltage (VSS) supply line.

The active area AA includes emission areas EA, a barrier area BA and ahole area HA.

Unit pixels, each of which includes a light emitting element 130, aredisposed in the emission areas EA, respectively. Each unit pixel may beconstituted by red (R), green (G) and blue (B) subpixels, as illustratedin FIG. 1, or may be constituted by red (R), green (G), blue (B) andwhite (W) subpixels. Each subpixel includes one light emitting element130, and a pixel driving circuit for independently driving the lightemitting element 130.

The pixel driving circuit includes a switching transistor TS, a drivingtransistor TD and a storage capacitor Cst.

The switching transistor TS turns on when a scan pulse is supplied to acorresponding scan line SL. In this state, a data signal supplied to acorresponding data line DL is supplied to the capacitor Cst and a gateelectrode of the driving transistor TD via the switching transistor TS.

The driving transistor TD controls current I supplied from acorresponding high-voltage (VDD) supply line to the light emittingelement 130, in response to the data signal supplied to the gateelectrode thereof, thereby adjusting the amount of light emitted fromthe light emission element 130. Even when the switching transistor TSturns off, the driving transistor TD supplies constant current I by avoltage charged in the storage capacitor Cst until a data signal of anext frame is supplied and, as such, the light emission element 130maintains emission of light.

FIG. 2 illustrates an organic light emitting display device according toa first embodiment of the present disclosure. As illustrated in FIG. 2,the driving transistor TD, which is designated by reference numeral“150”, includes an active layer 154 disposed on an active buffer layer114, a gate electrode 152 overlapping with the active layer 154 underthe condition that a gate insulating film 116 is interposed between theactive layer 154 and the gate electrode 152, and source and drainelectrodes 156 and 158 formed on an interlayer insulating film 102 whilecontacting the active layer 154.

The active layer 154 is made of at least one of an amorphoussemiconductor material, a polycrystalline semiconductor material or anoxide semiconductor material. The active layer 154 includes a channelregion, a source region and a drain region. The channel region overlapswith the gate electrode 152 under the condition that the gate insulatingfilm 116 is interposed between the channel region and the gate electrode152 and, as such, the channel region is defined between the sourceelectrode 156 and the drain electrode 158. The source region iselectrically connected to the source electrode 156 via a source contacthole passing through the gate insulating film 116 and the interlayerinsulating film 102. The drain region is electrically connected to thedrain electrode 158 via a drain contact hole passing through the gateinsulating film 116 and the interlayer insulating film 102. Amulti-buffer layer 112 and an active buffer layer 114 are disposedbetween the active layer 154 and a substrate 101. The multi-buffer layer112 functions to delay diffusion of moisture and/or oxygen penetratinginto the substrate 101. The multi-buffer layer 112 may be formed overthe entire upper surface of the substrate 101. The multi-buffer layer112 may provide an environment capable of more stably realizing thinfilm formation while enabling more effective execution of variousprocesses before execution of a main display panel fabrication process.The active buffer layer 114 performs functions of protecting the activelayer 154 and blocking various kinds of defects propagated from thesubstrate 101. At least one of the multi-buffer layer 112, the activebuffer layer 114 or the substrate 101 has a multilayer structure.

In this case, the uppermost layer of the multi-buffer layer 112contacting the active buffer layer 114 is made of a material havingetching characteristics different from those of the remaining layers ofthe multi-buffer layer 112, the active buffer layer 114 and the gateinsulating layer 116. The uppermost layer of the multi-buffer layer 112contacting the active buffer layer 114 is made of one of SiN_(x) andSiO_(x). The remaining layers of the multi-buffer layer 112, the activebuffer layer 114 and the gate buffer layer 116 are made of the other ofSiN_(x) and SiO_(x). For example, the uppermost layer of themulti-buffer layer 112 contacting the active buffer layer 114 is made ofSiN_(x), whereas the remaining layers of the multi-buffer layer 112, theactive buffer layer 114 and the gate buffer layer 116 are made ofSiO_(x).

The light emitting element 130 includes an anode 132 connected to thedrain electrode 158 of the driving transistor 150, at least one lightemitting stack 134 formed on the anode 132, and a cathode 136 formed onthe light emitting stack 134, to be connected to a low-voltage (VSS)supply line. Here, the low-voltage (VSS) supply line supplies a voltagelower than a high voltage supplied through a high-voltage (VDD) supplyline.

The anode 132 is electrically connected to the drain electrode 158 ofthe driving transistor 150 exposed through a pixel contact hole 126passing through a passivation film 124 and a planarization layer 104,which are disposed on the driving transistor 150. The anode 132 of eachsubpixel is disposed on the planarization layer 104 without beingcovered by a bank 138 such that the anode 132 is exposed.

When the anode 132 as described above is applied to a bottom emissiontype organic light emitting display device, the anode 132 is constitutedby a transparent conductive film made of indium tin oxide (ITO) orindium zinc oxide (IZO). On the other hand, when the anode 132 isapplied to a top emission type organic light emitting display device,the anode 132 is formed to have a multilayer structure including atransparent conductive film and an opaque conductive film having highreflection efficiency. The transparent conductive film is made of amaterial having a relatively high work function, for example, indium tinoxide (ITO) or indium zinc oxide (IZO). The opaque conductive film isformed to have a single-layer structure or a multilayer structureincluding Al, Ag, Cu, Pb, Mo, Ti or an alloy thereof. For example, theanode 132 is formed to have a structure in which a transparentconductive film, an opaque conductive film and a transparent conductivefilm are sequentially laminated.

The light emitting stack 134 is formed by laminating a hole transportlayer, a light emitting layer and an electron transport layer on theanode 132 in this order or in reverse order.

The cathode 136 is formed on upper surfaces and side surfaces of thelight emitting stack 134 and the bank 138, to face the anode 132 underthe condition that the light emitting stack 134 is interposed betweenthe anode 132 and the cathode 136.

An encapsulation unit 140 is formed to prevent penetration of externalmoisture or oxygen into the light emitting element 130, which is weakagainst moisture or oxygen. To this end, the encapsulation unit 140includes a plurality of inorganic encapsulation layers 142 and 146, andan organic encapsulation layer 144 disposed between adjacent ones of theinorganic encapsulation layers 142 and 146. The inorganic encapsulationlayer 146 is disposed at an uppermost position of the encapsulation unit140. In this case, the encapsulation unit 140 includes at least oneinorganic encapsulation layer 142 or 146 and at least one organic layer144. The following description will be given in conjunction with anexample in which the encapsulation unit 140 has a structure including afirst inorganic encapsulation layer 142 and a second inorganicencapsulation layer 146, and one organic encapsulation layer 144disposed between the first and second inorganic encapsulation layers 142and 146 in accordance with the present disclosure.

The first inorganic encapsulation layer 142 is formed on the substrate101 formed with the cathode 136 such that the first inorganicencapsulation layer 142 is disposed closest to the light emittingelement 130. The first inorganic encapsulation layer 142 is made of aninorganic insulating material capable of being deposited at lowtemperature, for example, silicon nitride (SiN_(x)), silicon oxide(SiO_(x)), silicon oxynitride (SiON) or aluminum oxide (Al₂O₃). As such,the inorganic encapsulation layer 142 may be deposited in alow-temperature atmosphere. Accordingly, it may be possible to preventdamage to the light emitting stack 134, which is weak in ahigh-temperature atmosphere during deposition of the first inorganicencapsulation layer 142.

The second inorganic encapsulation layer 146 is formed to cover upperand side surfaces of the organic encapsulation layer 144 and an exposedupper surface of the first inorganic encapsulation layer 142 not coveredby the organic encapsulation layer 144. As a result, upper and lowersurfaces of the organic encapsulation layer 144 are sealed by the firstand second inorganic encapsulation layers 142 and 146 and, as such, itmay be possible to minimize or prevent penetration of external moistureor oxygen into the organic encapsulation layer 144 or penetration ofmoisture or oxygen present within the organic encapsulation layer 144into the light emitting element 130. The second inorganic encapsulationlayer 146 is made of an inorganic insulating material such as siliconnitride (SiN_(x)), silicon oxide (SiO_(x)), silicon oxynitride (SiON) oraluminum oxide (Al₂O₃).

The organic encapsulation layer 144 serves as a buffer to buffer stressgenerated among layers during bending of the organic light emittingdisplay device while enhancing planarization performance. In addition,the organic encapsulation layer 144 is formed to have a greaterthickness than the inorganic encapsulation layers 142 and 146, in orderto prevent formation of cracks or pinholes caused by foreign matter. Theorganic encapsulation layer 144 is made of an organic insulatingmaterial such as acryl resin, epoxy resin, polyimide, polyethylene orsilicon oxycarbide (SiOC).

Upon formation of the organic encapsulation layer 144, an outer dam 128and an inner dam 108 are formed in order to restrict flowability of theorganic encapsulation layer 144.

As illustrated in FIG. 1, at least one outer dam 128 may be formed tocompletely enclose the active area AA where light emitting elements 130are disposed or may be formed only in an area between the active area AAand the non-active area NA. When a non-active area NA formed with aplurality of pads 180 is disposed at one side of the substrate 101, theouter dam 128 is disposed only at one side of the substrate 101. On theother hand, when non-active areas NA each formed with a plurality ofpads 180 are disposed at opposite sides of the substrate 101,respectively, outer dams 128 are disposed at the opposite sides of thesubstrate 101, respectively. When plural outer dams 128 are disposed,the outer dams 128 are disposed in parallel while being spaced apartfrom one another by a certain distance. By virtue of such an outer dam128, it may be possible to prevent diffusion of the organicencapsulation layer 144 into the non-active area NA.

As illustrated in FIG. 3, at least one inner dam 108 is disposed tocompletely enclose a substrate hole 120 disposed in the hole area HA. Inthis case, the signal lines 106 disposed around the inner dam 108 andthe substrate hole 120 while including the scan lines SL, the data linesDL, etc. extend along the circumference of the substrate hole 120 suchthat the signal lines 106 bypass the substrate hole 120.

Such an inner dam 108 is formed to have a single-layer structure or amultilayer structure including layers 108 a and 108 b, similarly to theouter dam 128. That is, each of the inner dam 108 and the outer dam 128is formed simultaneously with at least one of the planarization layer104, the bank 138 or a spacer (not shown), using the same material, and,as such, use of an additional mask process and an increase in costs maybe prevented. For example, the lower layer 108 a of the inner dam 108 ismade of the same material as the planarization layer 104, and the upperlayer 108 b of the inner dam 108 is made of the same material as thebank 138. By virtue of such an inner dam 108, the organic encapsulationlayer 144, which may function as a moisture penetration path, may beprevented from being diffused into the hole area HA.

The barrier area BA is disposed between the hole area HA and theemission areas EA disposed adjacent to the hole area HA. In the barrierarea BA, the above-described inner dam 108, at least one blocking groove110, a through hole 190 and a moisture penetration preventing layer 182are formed.

The through hole 190 is formed to pass through the hole area HA and aplurality of thin film layers disposed in an area around the hole areaHA. For example, the through hole 190 is formed to pass through the holearea HA and the inorganic insulating layers 112, 114, 116, and 102, thelight emitting stack 134, the cathode 136 and the inorganicencapsulation layers 142 and 146, which are disposed in the area aroundthe hole area HA, such that the upper surface of the substrate 101 or anupper surface of the multi-buffer layer 112 is exposed. In accordancewith formation of the through hole 190, portions of the inorganicinsulating layers 112, 114, 116, and 102, the light emitting stack 134,the inorganic encapsulation layers 142 and 146, etc. disposed in thehole area HA are removed and, as such, it may be possible to simplify alaser trimming process for forming the substrate hole 120.

Each blocking groove 110 is disposed between each inner dam 108 and thesubstrate hole 120. The blocking groove 110 is formed to pass through atleast one inorganic insulating layer of the multi-buffer layer 112, theactive buffer layer 114, the gate insulating film 116, or the interlayerinsulating film 102 disposed between the substrate 101 and theplanarization layer 104. In this case, side surfaces of the inorganicinsulating layers 114, 116, and 102 exposed through the blocking groove110 are formed to have a reversed taper shape such that the sidesurfaces form an acute angle or a right angle with respect to lowersurfaces of the inorganic insulating layers 114, 116, and 102 exposedthrough the blocking groove 110. By virtue of such a blocking groove110, each of the light emitting stack 134 and the cathode 136 isdisconnected without having continuance during formation thereof.Accordingly, even when external moisture penetrates along the lightemitting stack 134 disposed near the hole area HA, introduction of thepenetrated moisture into the emission area EA may be prevented ordelayed by the blocking groove 110. In addition, even when staticelectricity is introduced into the cathode 136 disposed near the holearea HA, diffusion of the introduced static electricity into theemission area EA may be prevented by the blocking groove 110.Furthermore, the blocking groove 110 exhibits great hardness, ascompared to organic insulating materials, and, as such, it may bepossible to prevent propagation of cracks into the emission area EAthrough removal of the inorganic insulating layers 114, 116, and 102,which may easily generate cracks when subjected to bending stress.

Meanwhile, portions of the first and second inorganic encapsulationlayers 142 and 146 disposed in the blocking groove 110 are formed to becurved along the side surfaces of the inorganic insulating layers 114,116, and 102 exposed through the blocking groove 110 while having areversed taper shape. Due to such a curvature, cracks may be easilygenerated at the first and second inorganic encapsulating layers 142 and146 and, as such, external moisture or oxygen may penetrate through thecracks formed at the first and second inorganic encapsulation layers 142and 146. To this end, the moisture penetration preventing layer 182 isdisposed on at least one of the first inorganic encapsulation layer 142or the second inorganic encapsulation layer 146 between the inner dam108 and the substrate hole 120 such that the moisture penetrationpreventing layer 182 overlaps with the blocking groove 110. The moisturepenetration preventing layer 182 is formed to have a single-layerstructure or a multilayer structure, using at least one of W, Mo, Co,Ag, Al, Cu, MoTi, Ta or Ti.

The moisture penetration preventing layer 182 is formed not only tooverlap with the blocking groove 110, but also to extend to the sidesurface of the light emitting stack 134 exposed through the through hole190. The moisture penetration preventing layer 182 is formed to coverside surfaces of the multi-buffer layer 112, the active buffer layer114, the gate insulating film 116, the interlayer insulating film 102,the light emitting stack 134, the cathode 136 and the first and secondinorganic encapsulation layers 142 and 146 exposed through the throughhole 190. As such, the moisture penetration preventing layer 182prevents external moisture or oxygen from penetrating into an outer sidesurface of the light emitting stack 134, an interface between the lightemitting stack 134 and the interlayer insulating film 102 and aninterface between the light emitting stack 134 and the cathode 136,which are exposed through the through hole 190.

The moisture penetration preventing layer 182 is formed after formationof the blocking groove 110 and the through hole 190. That is, themoisture penetration preventing layer 182 may be formed through aphotolithography process and an etching process or may be formed througha non-lithography process. As the non-lithography process, a laserchemical vapor deposition process, a laser induced forwards transfer(LIFT) process, an electrohydrodynamic (EHD) jet printing process or thelike may be used. In detail, the moisture penetration preventing layer182 may be formed by injecting a solution such as W(CO)6, Mo(CO)6,Co(CO)6 or the like onto the substrate 101 through a laser chemicalvapor deposition process. In this case, a conductive material is left as(CO) 6 is evaporated and, as such, forms the moisture penetrationpreventing layer 182. Alternatively, the moisture penetration preventinglayer 182 may be formed by injecting a conductive solution or conductivepowder of Ag, Al, Cu or the like onto the substrate 101 through a laserinduced forwards transfer (LIFT) process or an electrohydrodynamics(EHD) jet printing process. In this case, when the moisture penetrationpreventing layer 182 is injected onto the hole area HA, which is not adesired area for the moisture penetration preventing layer 182, themoisture penetration preventing layer 182 injected onto the hole area HAis removed through a laser trimming process. After the laser trimmingprocess, the moisture penetration preventing layer 182 injected onto adesired area may be cured and sintered.

The hole area HA is disposed within the active area AA and, as such, maybe enclosed by a plurality of subpixels SP each including one lightemitting element 130. At least one substrate hole 120 disposed in thehole area HA is illustrated as having a circular shape, but may beformed to have a polygonal shape or an oval shape. The substrate hole120 is formed to pass through the substrate 101. The substrate hole 120overlaps with the through hole 190 while having a smaller width than thethrough hole 190.

An electronic component including a camera, a speaker, a flash lightsource or a biometric sensor such as a fingerprint sensor is disposed inthe hole area HA so as to be inserted into the substrate hole 120. Thefollowing description will be given in conjunction with an example inwhich a camera module 160 is disposed in the hole area HA in accordancewith the present disclosure, as illustrated in FIG. 4.

The camera module 160 includes a camera lens 164 and a camera driver162.

The camera driver 162 is disposed at a lower surface of the substrate101, which is included in a display panel, such that the camera driver162 is connected to the camera lens 164.

The camera lens 164 is disposed within the substrate hole 120 extendingfrom a lower thin film layer (for example, the substrate 101 or a backplate) disposed at a lowermost position of the active area AA to anupper thin film layer (for example, a polarization plate 166) disposedat an uppermost position of the active area AA. Accordingly, the cameralens 164 is disposed to face a cover glass 168. In this case, thesubstrate hole 120 may be disposed to pass through the substrate 101,the inorganic insulating layers, and the polarization plate 166, or maybe disposed to pass through the substrate 101 and the polarization plate166.

As the camera module 160 is disposed within the active area AA, it maybe possible to minimize the bezel area, which is a non-display area ofthe display device.

FIG. 5 is a cross-sectional view illustrating an organic light emittingdisplay device according to a second embodiment of the presentdisclosure.

The organic light emitting display device illustrated in FIG. 5 includesthe same constituent elements as those of the organic light emittingdisplay device illustrated in FIG. 2, except that a black layer 184 isfurther included. Accordingly, no detailed description will be given ofthe same constituent elements for the sake of brevity.

The black layer 184 is formed over the moisture penetration preventinglayer 182 such that the black layer 184 has a greater width than themoisture penetration preventing layer 182. That is, the black layer 184is formed to cover upper and side surfaces of the moisture penetrationpreventing layer 182 disposed in the barrier area BA such that the blacklayer 184 contacts the upper and side surfaces of the moisturepenetration preventing layer 182. Accordingly, it may be possible toprevent externally incident light from being reflected by the moisturepenetration preventing layer 182 and, as such, the moisture penetrationpreventing layer 182 disposed in the barrier area BA is prevented frombeing visible.

The black layer 184 is formed through a photolithography process or anon-lithography process such as an inkjet process after sequentialformation of the through hole 190 and the moisture penetrationpreventing layer 182.

Meanwhile, although the light emitting stack 134 and the cathode 136illustrated in FIG. 2 or 5 have been described in conjunction with theexample in which the light emitting stack 134 and the cathode 136 havestructures disconnected by the blocking groove 110 without havingcontinuance, the light emitting stack 134 and the cathode 136 may havedisconnected structures without using the blocking groove 110, asillustrated in FIGS. 6A to 6C. That is, the light emitting stack 134 andthe cathode 136 may not be formed in a portion of the barrier area BAand the hole area HA surrounded by the inner dam 108 in accordance witha deposition process using a shadow mask. In this case, the outer sidesurface of the light emitting stack 134 illustrated in FIG. 6A isprotected by the inorganic encapsulation layers 142 and 146 and, assuch, the moisture penetration preventing layer 182 and the black layer184 are disposed over the inorganic encapsulation layers 142 and 146between the inner dam 108 and the substrate hole 120. On the other hand,the outer side surface of the light emitting stack 134 illustrated inFIG. 6B is disposed to face the moisture penetration preventing layer182 and, as such, is protected by the inorganic encapsulation layers 142and 146, the moisture penetration preventing layer 182 and the blacklayer 184. Otherwise, as illustrated in FIG. 6C, the outer side surfaceof the light emitting stack 134 is disposed to contact the moisturepenetration preventing layer 182 and, as such, is protected by themoisture penetration preventing layer 182 and the black layer 184.Accordingly, the outer surface of the light emitting stack 134 in eachof the cases illustrated in FIGS. 6A to 6C is protected by at least oneof the inorganic encapsulation layers 142 and 146, the moisturepenetration preventing layer 182, or the black layer 184 and, as such,it may be possible to prevent external moisture or oxygen frompenetrating into the light emitting stack 134.

FIG. 7 is a cross-sectional view illustrating a display device includinga substrate hole according to a third embodiment of the presentdisclosure.

The display device illustrated in FIG. 7 includes the same constituentelements as those of the display device illustrated in FIG. 2, exceptthat a touch sensor is further included. Accordingly, no detaileddescription will be given of the same constituent elements for the sakeof brevity.

The touch sensor includes a plurality of touch electrodes 192, and aplurality of bridges 194 connecting the touch electrodes 192.

At least one of each touch electrode 192 or each bridge 194 may beconstituted by a transparent conductive film made of ITO or IZO, may beconstituted by a mesh metal film having a mesh structure, or may beconstituted by a transparent conductive film as described above and amesh metal film disposed over or beneath the transparent conductivefilm. Here, the mesh metal film is formed to have a mesh structure,using at least one conductive layer made of Ti, Al, Mo, MoTi, Cu, Ta orITO while exhibiting better conductivity than the transparent conductivefilm. For example, the mesh metal film may be formed to have atriple-layer structure of Ti/Al/Ti, MoTi/Cu/MoTi, or Ti/Al/Mo. At leastone of the mesh metal film or each bridge 194 overlaps with the bank138.

One of each bridge 194 and each touch electrode 192 is disposed on oneof a touch buffer film 148 and the uppermost inorganic encapsulationlayer 146 included in the encapsulation unit 140, whereas the other ofeach bridge 194 and each touch electrode 192 is disposed on a touchinsulating film 198. That is, although each touch electrode 192 and eachbridge 194 illustrated in FIG. 7 have been described in conjunction withthe case in which each touch electrode 192 is disposed on the touchinsulating film 198, and each bridge 194 is disposed on the touch bufferfilm 148, each bridge 194 may be disposed on the touch insulating film198, and each touch electrode 192 may be disposed on the touch bufferfilm 148.

At least one of each touch electrode 192 or each bridge 194 as describedabove is formed simultaneously with the moisture penetration preventinglayer 182. To this end, the moisture penetration preventing layer 182 ismade of the same material as at least one of each touch electrode 192 oreach bridge 194.

The touch insulating film 198 includes touch contact holes 196 eachelectrically connecting corresponding ones of the bridges 194 and thetouch electrodes 192. At least one of the touch insulating film 198 orthe touch buffer film 148 extends to the barrier area BA, to cover theouter side surface of the light emitting stack 134 exposed through thethrough hole 190.

A touch protection film 118 is disposed on the touch insulating film198, on which the touch electrodes 192 are disposed, in order to protectthe touch sensors. The touch protection film 118 is made of an inorganicinsulating material or an organic insulating material. A black matrix188 is disposed on the touch protection film 118 such that the blackmatrix 188 overlaps with the bank 138. The black matrix 188 minimizesreflection of external light, thereby achieving an enhancement invisibility without using a polarization plate. Accordingly, the presentdisclosure achieves structural simplification in that use of apolarization plate is eliminated. The black matrix 188 is made of thesame material as the black layer 184 overlapping with the moisturepenetration preventing layer 182. The black layer 184 may be disposed tooverlap with the moisture penetrating preventing layer 182 under thecondition that the touch insulating film 198 is disposed between theblack layer 184 and the moisture penetration preventing layer 182, ormay be disposed on the moisture penetration preventing layer 182, tophysically contact the moisture penetration preventing layer 182 withoutinterposition of the touch insulating film 198.

As such, in the present disclosure, it may be possible to preventexternal moisture or oxygen from penetrating into an outer surface ofthe light emitting stack 134 by the moisture penetration preventinglayer 182, the touch insulating film 198, the touch buffer film 148, andthe black layer 184. Accordingly, an enhancement in reliability may beachieved. In addition, in the present disclosure, it may be possible toprevent reflection of external light by the black layer 184 withoutusing a polarization plate. Accordingly, structural simplification and areduction in costs may be achieved.

FIGS. 8A to 8H are cross-sectional views explaining a method formanufacturing the organic light emitting display device illustrated inFIG. 7 according to an embodiment of the present disclosure.

In detail, the multi-buffer layer 112 and the active buffer layer 114are formed on the substrate 101, as illustrated in FIG. 8A. Here, thesubstrate 101 is made of a plastic material having flexibility, to bebendable. For example, the substrate 101 is made of polyimide (PI),polyethylene terephthalate (PET), polyethylene naphthalate (PEN),polycarbonate (PC), polyethersulfone (PES), polyarylate (PAR),polysulfone (PSF), or cyclic-olefin copolymer (COC).

Thereafter, the active layer 154 is formed on the active buffer layer114 through a photolithography process and an etching process. The gateinsulating film 116, which is made of an inorganic insulating material,is then formed over the active layer 154. The gate insulating electrode152 is then formed on the gate insulating film 116, together with alower pad electrode, through a photolithography process and an etchingprocess. Subsequently, the interlayer insulating film 102 made of aninorganic insulating material is formed. The interlayer insulating film102 and the gate insulating film 116 are then patterned through aphotolithography process and an etching process, thereby forming sourceand drain contact holes (not shown), through which the active layer 154is exposed. Thereafter, the interlayer insulating film 102, the gateinsulating film 116 and the active buffer layer 114 are patternedthrough a photolithography process and an etching process, therebyforming the blocking groove 110, through which the upper surface of themulti-buffer layer 112 is exposed. At this time, a portion of themulti-buffer layer 112 may also be patterned in accordance with theetching process and, as such, a side surface of the multi-buffer layer112 may be exposed through the blocking groove 110.

Subsequently, the source and drain electrodes 156 and 158 are formed onthe interlayer insulating film 102 through a photolithography processand an etching process. The planarization layer 104 and the anode 132are then sequentially formed through a photolithography process and anetching process. Subsequently, the bank 138, the inner dam 108, and theouter dam 128 are simultaneously formed through a photolithographyprocess and an etching process using the same mask.

Thereafter, the organic light emitting layer 134 and the cathode 136 aresequentially formed on the substrate 101 formed with the bank 138through a deposition process using a shadow mask. In this case, thelight emitting stack 134 and the cathode 136 are disconnected withouthaving continuance by the blocking groove 110. Next, at least oneinorganic encapsulation layer (the inorganic encapsulation layers 142and 146 in the illustrated case) and at least one organic encapsulationlayer (the organic encapsulation layer 144 in the illustrated case) arelaminated over the cathode 136, thereby forming the encapsulation unit140. In this case, the organic encapsulation layer 144 is formed in anarea, except for the hole area HA and the non-active area NA, by virtueof the inner dam 108 and the outer dam 128.

Thereafter, the inorganic encapsulation layers 142 and 146, the cathode136, the light emitting stack 134, the interlayer insulating film 102,the gate insulating film 116, the active buffer layer 114 and themulti-buffer layer 112 are patterned through a photolithography processand an etching process, thereby forming the through hole 190, asillustrated in FIG. 8B.

Subsequently, an inorganic or organic insulating material is coated overthe entire upper surface of the substrate 101 formed with the throughhole 190, thereby forming the touch buffer film 148, as illustrated inFIG. 8C. The bridges 194 and the moisture penetration preventing layer182 are then simultaneously formed on the substrate 101 formed with thetouch buffer film 148 through a photolithography process and an etchingprocess. An inorganic or organic insulating material is then coated overthe entire upper surface of the substrate 101 formed with the bridges194 and the moisture penetration preventing layer 182, thereby formingthe touch insulating film 198, as illustrated in FIG. 8D. Thereafter,the touch insulating film 198 is patterned through a photolithographyprocess and an etching process, thereby forming the touch contact holes196. At this time, portions of the touch insulating film 198 and thetouch buffer film 148 disposed in the hole area HA are also removed.Subsequently, the touch electrodes 196 are formed on the substrate 101formed with the touch contact holes 196 through a photolithographyprocess and an etching process, as illustrated in FIG. 8E. The touchprotection film 118 to protect touch sensors is then formed on thesubstrate 101 through a photolithography process and an etching process,as illustrated in FIG. 8F. Next, the black matrix 188 and the blacklayer 184 are simultaneously formed on the substrate 101 formed with thetouch protection film 118 through a photolithography process and anetching process, as illustrated in FIG. 8G. Finally, a desired portionof the substrate 101 is removed through a laser trimming process,thereby forming the substrate hole 120, as illustrated in FIG. 8H.

FIG. 9 is a cross-sectional view illustrating an organic light emittingdisplay device according to a fourth embodiment of the presentdisclosure.

The organic light emitting display device illustrated in FIG. 9 includesthe same constituent elements as those of the organic light emittingdisplay device illustrated in FIG. 5, except that a side cover layer 186is further included. Accordingly, no detailed description will be givenof the same constituent elements.

The side cover layer 186 is formed to cover outer side surfaces of themoisture penetration preventing layer 182 and the black layer 184. Theside cover layer 186 is made of a frit-based sealant. The side coverlayer 186 made of the frit-based sealant exhibits high bonding force toa thin film layer disposed adjacent thereto and, as such, may preventpenetration of external moisture or oxygen into the outer side surfaceand interface of the light emitting stack 134. The side cover layer 186,which is disposed to cover the outer side surface of the light emittingstack 134, lengthens a moisture penetration path, thereby preventingdegradation of the light emitting stack 134.

FIGS. 10A to 10D are cross-sectional views explaining a method formanufacturing the organic light emitting display device illustrated inFIG. 9 according to an embodiment of the present disclosure.

First, as illustrated in FIG. 10A, thin film transistors designated byreference numeral “150”, the blocking groove 110, the light emittingelements 130, the encapsulation units 140 and the through hole 190 areformed in accordance with the manufacturing method illustrated in FIGS.8A and 8B. Thereafter, the moisture penetration preventing layer 182 andthe black layer 184 are sequentially formed in the barrier area BA, asillustrated in FIG. 10B. Subsequently, a frit-based sealant is coated tocover the black layer 184, and is then cured, thereby forming the sidecover layer 186, as illustrated in FIG. 10C. Portions of the substrate101 and the side cover layer 186 disposed in the hole area HA are thenremoved through a laser trimming process, thereby forming the substratehole 120, as illustrated in FIG. 10D. During the laser trimming process,the side cover layer 186 may be melted and then re-sintered to cover theouter side surface of the substrate 101 exposed through the substratehole 120.

As such, in the present disclosure, the outer side surface of the lightemitting stack 134 is sealed by the moisture penetration preventinglayer 182, the black layer 184 and the side cover layer 186.Accordingly, it may be possible to prevent external moisture or oxygenfrom penetrating into the interface of the light emitting stack 134,thereby preventing degradation of the light emitting stack.

FIG. 11 is a cross-sectional view illustrating an organic light emittingdisplay device according to a fifth embodiment of the presentdisclosure.

The organic light emitting display device illustrated in FIG. 11includes the same constituent elements as those of the organic lightemitting display device illustrated in FIG. 9, except that the sidecover layer 186 extends from at least one of the touch insulating film198 or the touch buffer film 148. Accordingly, no detailed descriptionwill be given of the same constituent elements.

The side cover layer 186 is formed to cover the outer side surface ofthe moisture penetration preventing layer 182. The side cover layer 186extends from at least one of the touch insulating film 198 or the touchbuffer film 148. For example, the side cover layer 186 includes firstand second side cover layers 186 a and 186 b, which are sequentiallylaminated. The first side cover layer 186 a extends from the touchbuffer film 148, to cover the moisture penetration preventing layer 182.The second side cover layer 186 b extends from the touch insulating film198, to cover the first side cover layer 186 a.

As such, it may be possible to prevent external moisture or oxygen frompenetrating into the light emitting stack 134 by the moisturepenetration preventing layer 182 and the side cover layer 186overlapping with the outer side surface of the light emitting stack 134and the blocking groove 110.

Meanwhile, although the black layer 184 is shown in FIG. 11 as being notdisposed on the moisture penetration preventing layer 182, the blacklayer 184 as shown in FIG. 5 may be disposed on the moisture penetrationpreventing layer 182, to physically contact the moisture penetrationpreventing layer 182. In addition, the touch buffer film 148 and thetouch insulating film 198 may be disposed between the black layer 184and the moisture penetration preventing layer 182 such that the blacklayer 184 and the moisture penetration preventing layer 182 may notphysically contact each other.

FIGS. 12A to 12C are cross-sectional views explaining a method formanufacturing the organic light emitting display device illustrated inFIG. 9 according to an embodiment of the present disclosure.

First, as illustrated in FIG. 12A, the thin film transistors 150, theblocking groove 110, the light emitting elements 130, the encapsulationunits 140, and the through hole 190 are formed in accordance with themanufacturing method illustrated in FIGS. 8A and 8B. Thereafter, themoisture penetration preventing layer 182 is formed in the barrier areaBA, and an inorganic or organic insulating material is coated over theentire upper surface of the resultant structure, thereby forming thetouch buffer film 148 and the first side cover layer 186 a, asillustrated in FIG. 12B. The bridges 194 are then formed on thesubstrate 101 formed with the touch buffer film 148 and the first sidecover layer 186 a through a photolithography process and an etchingprocess. Subsequently, an inorganic or organic insulating material iscoated over the entire upper surface of the substrate 101 formed withthe bridges 194, thereby forming the touch insulating film 198 and thesecond side cover layer 186 b. Thereafter, the touch insulating film 198is patterned through a photolithography process and an etching process,thereby forming the touch contact holes 196. The touch electrodes 196are then formed on the substrate 101 formed with the touch contact holes196 through a photolithography process and an etching process. Next,portions of the first and second side cover layers 186 a and 186 b andthe substrate 101 disposed in the hole area HA are removed through alaser trimming process, thereby forming the substrate hole 120, asillustrated in FIG. 12C.

As such, in the present disclosure, the outer side surface of the lightemitting stack 134 is sealed by the moisture penetration preventinglayer 182, the black layer 184, and the side cover layer 186, therebypreventing external moisture or oxygen from penetrating into theinterface of the light emitting stack 134. Accordingly, degradation ofthe light emitting stack 134 may be prevented.

As apparent from the above description, the present disclosure providesthe following effects.

As the camera module is disposed within the active area in accordancewith the present disclosure, it may be possible to minimize the bezelarea, which is a non-display area of the display device.

In addition, in accordance with the present disclosure, the moisturepenetration preventing layer is disposed to overlap with the lightemitting stack disposed between the substrate hole and the inner damand, as such, it may be possible to prevent external moisture or oxygenfrom penetrating into the active area.

Furthermore, in accordance with the present disclosure, the black layeris disposed on the moisture penetration preventing layer and, as such,it may be possible to prevent externally incident light from beingreflected by the moisture penetration preventing layer. Accordingly, anenhancement in visibility may be achieved.

It will be apparent to those skilled in the art that variousmodifications and variations can be made in the present inventionwithout departing from the spirit or scope of the invention. Thus, it isintended that the present invention cover the modifications andvariations of this invention provided they come within the scope of theappended claims and their equivalents.

What is claimed is:
 1. A display device comprising: a plurality of lightemitting elements disposed on a substrate, each of the light emittingelements comprising a respective light emitting stack; a substrate holepassing through the substrate while being surrounded by the lightemitting elements; an inner dam disposed between the substrate hole andthe light emitting elements; and a moisture penetration preventing layerdisposed between the inner dam and the substrate hole while overlappingwith the light emitting stacks.
 2. The display device according to claim1, further comprising: a blocking groove disposed between the inner damand the substrate hole while overlapping with the moisture penetrationpreventing layer, the blocking groove having a reversed taper shape. 3.The display device according to claim 1, further comprising: a throughhole disposed to surround the substrate hole while passing through thelight emitting stacks, wherein the moisture penetration preventing layeris disposed on side surfaces of the light emitting stacks exposedthrough the through hole.
 4. The display device according to claim 1,further comprising: a black layer disposed to cover upper and sidesurfaces of the moisture penetration preventing layer.
 5. The displaydevice according to claim 1, wherein the moisture penetration preventinglayer is formed to have a single-layer structure or a multilayerstructure, using at least one of W, Mo, Co, Ag, Al, Cu, MoTi, Ta, or Ti.6. The display device according to claim 1, further comprising: a sidecover layer made of a frit-based sealant, the side cover layer coveringthe moisture penetration preventing layer.
 7. The display deviceaccording to claim 1, further comprising: an encapsulation unit disposedon the light emitting elements; and a touch sensor disposed on theencapsulation unit, the touch sensor comprising a touch electrode and abridge.
 8. The display device according to claim 7, wherein the moisturepenetration preventing layer is made of the same material as at leastone of the touch electrode or the bridge, and is disposed on a sameplane as the at least one of the touch electrode or the bridge.
 9. Thedisplay device according to claim 7, further comprising: a touch bufferfilm disposed between the touch sensor and the encapsulation unit; and atouch insulating film disposed between the touch electrode and thebridge.
 10. The display device according to claim 9, further comprising:a side cover layer disposed on the moisture penetration preventing layerwhile extending from at least one of the touch buffer film or the touchinsulating film.
 11. The display device according to claim 9, furthercomprising: a bank disposed without covering anode electrodes of thelight emitting elements such that the anode electrodes are exposed; ablack matrix disposed over the touch sensor while overlapping with thebank; and a black layer disposed on upper and side surfaces of themoisture penetration preventing layer.
 12. The display device accordingto claim 11, wherein the black layer is made of the same material as theblack matrix.
 13. The display device according to claim 11, wherein theblack layer contacts the moisture penetration preventing layer.
 14. Thedisplay device according to claim 11, wherein at least one of the touchinsulating film or the touch buffer film is disposed between the blacklayer and the moisture penetration preventing layer.
 15. The displaydevice according to claim 1, further comprising: a camera moduledisposed within the substrate hole.